Apparatus, systems and methods for impulse noise detection and mitigation

ABSTRACT

In accordance with embodiments disclosed herein, there are provided apparatus, systems and methods for impulse noise detection and mitigation. For example, in one embodiment such means include, means for detecting impulse noise; means for classifying the detected impulse noise into one of a plurality of impulse noise classes affecting communications on a Digital Subscriber Line (DSL line); means for selecting a noise mitigation strategy from among a plurality of noise mitigation strategies; means for applying the selected noise mitigation strategy; and means for validating application of the noise mitigation strategy.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

TECHNICAL FIELD

The subject matter described herein relates generally to the field ofcomputing, and more particularly, to apparatuses, systems and methodsfor impulse noise mitigation.

BACKGROUND

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also correspond toembodiments of the claimed subject matter.

In the telecommunication arts, Digital Subscriber Lines (DSL lines)provide internet connectivity to subscribers, including residential andbusiness users. In the course of operating a DSL line, it is common forpeople to turn on and off devices that create impulses affectingcommunication on the DSL lines. Such impulses are not always present,but when caused by, for example, turning on a device, the impulse noisemay completely wipe out transmitted DSL signal communications or causesevere degradation to them. Washers, dryers, microwaves, and other suchdevices are capable of creating electrical surges that interfere withthe DSL communications on a DSL line. To remedy such interference, it iscommon for error correction code (ECC) to be used, but ECC has a longtime span and when combined with interleaving techniques, the ECC andinterleaved DSL communication signals result in a long delay (exhibitedas latency) because communications must be buffered so that data can berecovered from a damaged signal, resulting in an ongoing latency forongoing latency that is not acceptable for delay sensitive applications.

Moreover, because the ECC and interleaving may be utilized over a longperiod of time, it may appear as the modem itself is performing at lessthan optimal levels. Because ECC adds redundancy, the net rate will bedecreased. Should the redundancy owing to the ECC continue to be added,even if there is no impulse noise present, overall operation of themodem will suffer as the redundancy is being introduced to solve a nolonger existing problem.

The present state of the art may therefore benefit from apparatuses,systems, and methods for impulse noise detection and mitigation as isdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example, and not by way oflimitation, and will be more fully understood with reference to thefollowing detailed description when considered in connection with thefigures in which:

FIG. 1 illustrates an exemplary architecture in which embodiments mayoperate;

FIG. 2A illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 2B illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 2C illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 3 illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 4 illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 5 illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 6 illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIG. 7 illustrates an alternative exemplary architecture in accordancewith which embodiments may operate;

FIGS. 8 and 9 are flow diagrams illustrating methods for impulse noisedetection and mitigation in accordance with described embodiments; and

FIG. 10 shows a diagrammatic representation of a system in accordancewith which embodiments may operate, be installed, integrated, orconfigured.

DETAILED DESCRIPTION

Described herein are apparatuses, systems, and methods for impulse noisedetection and mitigation. In accordance with one embodiment, means forimpulse noise detection and mitigation are disclosed. Such means mayinclude, for example, means for detecting impulse noise affectingcommunications on a Digital Subscriber Line (DSL line); means forclassifying the detected impulse noise into one of a plurality ofimpulse noise classes; means for selecting a noise mitigation strategyfrom among a plurality of noise mitigation strategies; means forapplying the selected noise mitigation strategy; and means forvalidating application of the noise mitigation strategy.

According to one embodiment, validation includes comparing correctedsignals with uncorrected signals or passing the signals to anotherfilter and then comparing the filtered signals with uncorrected signals.Thus, a “corrected” signal may be a signal that has undergone a noisemitigation strategy or filtering, or both. In other embodiments, thereare multiple corrected signals to compare, and thus, validation isperformed for the multiple corrected signals. Where more than onefiltering or noise mitigation strategy provides some beneficial effect,a scoring mechanism can provide for systematic selection of the mostdesirable filter or noise mitigation strategy applied, or the bestcombination of filters and/or noise mitigation strategies applied in thegeneration of a corrected signal, as appropriate. For example, while thebest reference signal may be the most desirable to apply to a primarysignal carrying a DSL signal or DSL traffic, it may not be knowable inadvance which of multiple reference signals is the best one. Therefore,in certain embodiments, cancellation is applied from one referencesignal to another reference signal, without involving the primarysignal, and then a positive effect of cancellation between referencesignals provides an indication of cancellation that may be applied tothe primary signal. Such a technique helps to avoid the additional DSLsignal energy on the primary line as the second reference line subjectedto cancellation may be subject to the same interference and impulsenoise as the primary line but will not be saturated by DSL signal dataas is the case with a primary line carrying an active DSL signal.

In one embodiment, a reference channel is used in accordance with agiven impulse noise mitigation strategy. The reference channel isseparate from a primary channel used to carry the DSL communication(e.g., payload data and other information transmitted on the DSL linepursuant to providing DSL services to a DSL subscriber). Impulse noisemay be attempted to be detected on all available channels, but thedescribed mechanisms will nevertheless engage even when impulse is onlydetected on a single channel, which may be a reference channel or theprimary channel. Accordingly, impulse noise characteristics may beidentified based on the primary channel or the reference channel orboth. Clustering may be applied to collected impulse noise samples andimpulse noise characteristics to provide impulse noise cancellation andmitigation strategies. Detected impulse noises may then be mitigatedbased on an applied mitigation strategy taken from the available impulsenoise mitigation strategies.

Certain entities may provide impulse noise detection and mitigationthrough the provisioning of a so enabled device, such as a DSL modem, anappropriate DSL modem chipset, a signal optimizer communicativelyinterfaced between a DSL modem and a DSL line, or via a service whichperforms computation and optimization instructions for a DSL servicesubscriber. In some embodiments, such a service is provided inconjunction with a compatible device as is described herein.

Impulse noise detection and mitigation services may be provided by athird party, distinct from the DSL operator which provides the DSLservices to the DSL service subscriber. For instance, such a serviceprovider may attempt to cancel the impulse noises as they occur so thatan operator of the DSL service sees a minimum of the impulse noise orpotentially none at all. Monitoring lines, pre-qualifying lines, or bothfor the sake of impulse cancellation may further benefit applicationlayer controls (e.g. ARQ), regardless of whether or not hardware isdeployed. For example, such monitoring and pre-qualification could helpshape a deployment strategy so that more expensive and sophisticatedhardware is deployed in those locations where the most benefit can beattained, and locations which are determined to have a lesser benefitcould be delayed or simply not selected. Further still, monitoring oflines can provide further data points upon which effectiveness ofdeployed impulse noise detection and mitigation hardware can beevaluated or by which locations in need of such hardware could beidentified as the operational landscape of DSL system changes over time.Where utilized, real-time impulse noise mitigation improves customerexperience for the DSL subscriber through improved and more reliableperformance, and by extension, improves business conditions for the DSLoperator through enhanced customer satisfaction and decreased technicalsupport for intermittent communication faults or degraded DSL modemperformance.

A third party service provider of impulse noise detection and mitigationservices may additionally pass information to upper communication layers(e.g., ARQ) so that the upper layers can customize better solutions forthe impulse noise cancellation. For instance, In practice, even whereimpulse noise cancellation (INC) hardware is present, it maynevertheless be beneficial to jointly optimize ECC, INC, or even ECC,INC, and ARQ. Therefore, data collected from the monitoring of lines,may be utilized to optimize ECC and ARQ operational parameters, suchthat upper layers can customize their solutions by combining INC/ECC/ARQfor the best possible performance of a customer's active DSL line.

In the following description, numerous specific details are set forthsuch as examples of specific systems, languages, components, etc., inorder to provide a thorough understanding of the various embodiments. Itwill be apparent, however, to one skilled in the art that these specificdetails need not be employed to practice the disclosed embodiments. Inother instances, well known materials or methods have not been describedin detail in order to avoid unnecessarily obscuring the disclosedembodiments.

In addition to various hardware components depicted in the figures anddescribed herein, embodiments further include various operations whichare described below. The operations described in accordance with suchembodiments may be performed by hardware components or may be embodiedin machine-executable instructions, which may be used to cause ageneral-purpose or special-purpose processor programmed with theinstructions to perform the operations. Alternatively, the operationsmay be performed by a combination of hardware and software, includingsoftware instructions that perform the operations described herein viamemory and one or more processors of a computing platform.

Embodiments also relate to a system or apparatus for performing theoperations herein. The disclosed system or apparatus may be speciallyconstructed for the required purposes, or it may comprise a generalpurpose computer selectively activated or reconfigured by a computerprogram stored in the computer. Such a computer program may be stored ina non-transitory computer readable storage medium, such as, but notlimited to, any type of disk including floppy disks, optical disks,flash, NAND, solid state drives (SSDs), CD-ROMs, and magnetic-opticaldisks, read-only memories (ROMs), random access memories (RAMs), EPROMs,EEPROMs, magnetic or optical cards, or any type of media suitable forstoring non-transitory electronic instructions, each coupled to acomputer system bus. In one embodiment, a non-transitory computerreadable storage medium having instructions stored thereon, causes oneor more processors within an apparatus to perform the methods andoperations which are described herein. In another embodiment, theinstructions to perform such methods and operations are stored upon anon-transitory computer readable medium for later execution.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus nor are embodimentsdescribed with reference to any particular programming language. It willbe appreciated that a variety of programming languages may be used toimplement the teachings of the embodiments as described herein.

FIG. 1 illustrates an exemplary architecture 100 in which embodimentsmay operate in compliance with the G.997.1 standard (also known asG.ploam). Asymmetric Digital Subscriber Line (ADSL) systems (one form ofDigital Subscriber Line (DSL) systems), which may or may not includesplitters, operate in compliance with the various applicable standardssuch as ADSL1 (G.992.1), ADSL-Lite (G.992.2), ADSL2 (G.992.3),ADSL2-Lite G.992.4, ADSL2+ (G.992.5) and the G.993.x emergingVery-high-speed Digital Subscriber Line or Very-high-bitrate DigitalSubscriber Line (VDSL) standards, as well as the G.991.1 and G.991.2Single-Pair High-speed Digital Subscriber Line (SHDSL) standards, allwith and without bonding.

The G.997.1 standard specifies the physical layer management for ADSLtransmission systems based on the clear, Embedded Operation Channel(EOC) defined in G.997.1 and use of indicator bits and EOC messagesdefined in the G.992.x, G.993.x and G.998.4 standards. Moreover, G.997.1specifies network management elements content for configuration, faultand performance management. In performing the disclosed functions,systems may utilize a variety of operational data (which includesperformance data) that is available at an Access Node (AN).

In FIG. 1, users terminal equipment 102 (e.g., a Customer PremisesEquipment (CPE) device or a remote terminal device, network node, LANdevice, etc.) is coupled to a home network 104, which in turn is coupledto a Network Termination (NT) Unit 108. Multiple xTU devices (“allTransceiver Unit” devices) are further depicted. An xTU providesmodulation for a DSL loop or line (e.g., DSL, ADSL, VDSL, etc.). In oneembodiment, NT unit 108 includes an xTU-R (xTU Remote), 122 (forexample, a transceiver defined by one of the ADSL or VDSL standards) orany other suitable network termination modem, transceiver or othercommunication unit. NT unit 108 also includes a Management Entity (ME)124. Management Entity 124 may be any suitable hardware device, such asa microprocessor, microcontroller, or circuit state machine in firmwareor hardware, capable of performing as required by any applicablestandards and/or other criteria. Management Entity 124 collects andstores, among other things, operational data in its ManagementInformation Base (MIB), which is a database of information maintained byeach ME capable of being accessed via network management protocols suchas Simple Network Management Protocol (SNMP), an administration protocolused to gather information from a network device to provide to anadministrator console/program; via Transaction Language 1 (TL1)commands, TL1 being a long-established command language used to programresponses and commands between telecommunication network elements; orvia a TR-69 based protocol. “TR-69” or “Technical Report 069” is inreference to a DSL Forum technical specification entitled CPE WANManagement Protocol (CWMP) which defines an application layer protocolfor remote management of end-user devices. XML or “eXtended MarkupLanguage” compliant programming and interface tools may also be used.

Each xTU-R 122 in a system may be coupled with an xTU-C (xTU Central) ina Central Office (CO) or other central location. The xTU-C 142 islocated at an Access Node (AN) 114 in Central Office 146. A ManagementEntity (ME) 144 likewise maintains an MIB of operational data pertainingto xTU-C 142. The Access Node 114 may be coupled to a broadband network106 or other network, as will be appreciated by those skilled in theart. Each of xTU-R 122 and xTU-C 142 are coupled together by aU-interface/loop 112, which in the case of ADSL may be a twisted pairline, such as a telephone line, which may carry other communicationservices besides DSL based communications. Apparatus 170 may be managedor operated by a service provider of the DSL services or may be operatedby a third party, separate from the entity which provides DSL servicesto end-users. Thus, in accordance with one embodiment apparatus 170 isoperated and managed by an entity which is separate and distinct from atelecommunications operator responsible for a plurality of digitalcommunication lines. Management Entity 124 or Management Entity 144 mayfurther store information collected from apparatus 170 within anassociated MIB.

Several of the interfaces shown in FIG. 1 are used for determining andcollecting operational data. The Q interface 126 provides the interfacebetween the Network Management System (NMS) 116 of the operator and ME144 in Access Node 114. Parameters specified in the G.997.1 standardapply at the Q interface 126. The near-end parameters supported inManagement Entity 144 may be derived from xTU-C 142, while far-endparameters from xTU-R 122 may be derived by either of two interfacesover the U-interface. Indicator bits and EOC messages may be sent usingembedded channel 132 and provided at the Physical Medium Dependent (PMD)layer, and may be used to generate the required xTU-R 122 parameters inME 144. Alternately, the Operations, Administration and Maintenance(OAM) channel and a suitable protocol may be used to retrieve theparameters from xTU-R 122 when requested by Management Entity 144.Similarly, the far-end parameters from xTU-C 142 may be derived byeither of two interfaces over the U-interface. Indicator bits and EOCmessage provided at the PMD layer may be used to generate the requiredxTU-C 142 parameters in Management Entity 124 of NT unit 108.Alternately, the OAM channel and a suitable protocol may be used toretrieve the parameters from xTU-C 142 when requested by ManagementEntity 124.

At the U-interface (also referred to as loop 112), there are twomanagement interfaces, one at xTU-C 142 (the U-C interface 157) and oneat xTU-R 122 (the U-R interface 158). The U-C interface 157 providesxTU-C near-end parameters for xTU-R 122 to retrieve over theU-interface/loop 112. Similarly, the U-R interface 158 provides xTU-Rnear-end parameters for xTU-C 142 to retrieve over the U-interface/loop112. The parameters that apply may be dependent upon the transceiverstandard being used (for example, G.992.1 or G.992.2). The G.997.1standard specifies an optional Operation, Administration, andMaintenance (OAM) communication channel across the U-interface. If thischannel is implemented, xTU-C and xTU-R pairs may use it fortransporting physical layer OAM messages. Thus, the xTU transceivers 122and 142 of such a system share various operational data maintained intheir respective MIBs.

Depicted within FIG. 1 is apparatus 170 operating at various optionallocations in accordance with several alternative embodiments. Forexample, in accordance with one embodiment, apparatus 170 is locatedwithin terminal equipment 102 connecting the DSL line to a LAN whichestablishes home network 104. Alternatively, the apparatus 170 may beconnected with the phone line that supplies the DSL connection and theapparatus 170 then in turn connects with the terminal equipment 102which then is connected to a LAN which establishes home network 104. Inone embodiment apparatus 170 operates as a DSL modem, such as a CustomerPremises (CPE) modem. In another embodiment, apparatus 170 operates as acontroller card or as a chipset within a user's terminal equipment 102(e.g., a Customer Premises Equipment (CPE) device or a remote terminaldevice, network node, etc.) connecting the DSL line to the home network104 as depicted. In another embodiment, apparatus 170 operates as aseparate and physically distinct stand alone unit which is connectedbetween the user's terminal equipment 102 and a DSL line or loop. Forexample, apparatus 170 may operate as a stand-alone signal conditioningdevice. In yet another embodiment, apparatus 170 is connected with a NTunit 108 or with xTU-R 122 over the G-interface 159.

As used herein, the terms “user,” “subscriber,” and/or “customer” referto a person, business and/or organization to which communicationservices and/or equipment are and/or may potentially be provided by anyof a variety of service provider(s). Further, the term “customerpremises” refers to the location to which communication services arebeing provided by a service provider. For an example Public SwitchedTelephone Network (PSTN) used to provide DSL services, customer premisesare located at, near and/or are associated with the network termination(NT) side of the telephone lines. Example customer premises include aresidence or an office building.

As used herein, the term “service provider” refers to any of a varietyof entities that provide, sell, provision, troubleshoot and/or maintaincommunication services and/or communication equipment. Example serviceproviders include a telephone operating company, a cable operatingcompany, a wireless operating company, an internet service provider, orany service that may independently or in conjunction with a broadbandcommunications service provider offer services that diagnose or improvebroadband communications services (DSL, DSL services, cable, etc.).

Additionally, as used herein, the term “DSL” refers to any of a varietyand/or variant of DSL technology such as, for example, Asymmetric DSL(ADSL), High-speed DSL (HDSL), Symmetric DSL (SDSL), and/or Veryhigh-speed/Very high-bit-rate DSL (VDSL). Such DSL technologies arecommonly implemented in accordance with an applicable standard such as,for example, the International Telecommunications Union (I.T.U.)standard G.992.1 (a.k.a. G.dmt) for ADSL modems, the I.T.U. standardG.992.3 (a.k.a. G.dmt.bis, or G.adsl2) for ADSL2 modems, I.T.U. standardG.992.5 (a.k.a. G.adsl2plus) for ADSL2+ modems, I.T.U. standard G.993.1(a.k.a. G.vdsl) for VDSL modems, I.T.U. standard G.993.2 for VDSL2modems, I.T.U. standard G.993.5 for DSL modems supporting Vectoring,I.T.U. standard G.998.4 for DSL modems supporting retransmissionfunctionality, I.T.U. standard G.994.1 (G.hs) for modems implementinghandshake, and/or the I.T.U. G.997.1 (a.k.a. G.ploam) standard formanagement of DSL modems.

References to connecting a DSL modem and/or a DSL communication serviceto a customer are made with respect to exemplary Digital Subscriber Line(DSL) equipment, DSL services, DSL systems and/or the use of ordinarytwisted-pair copper telephone lines for distribution of DSL services, itshould be understood that the disclosed methods and apparatus tocharacterize and/or test a transmission medium for communication systemsdisclosed herein may be applied to many other types and/or variety ofcommunication equipment, services, technologies and/or systems. Forexample, other types of systems include wireless distribution systems,wired or cable distribution systems, coaxial cable distribution systems,Ultra High Frequency (UHF)/Very High Frequency (VHF) radio frequencysystems, satellite or other extra-terrestrial systems, cellulardistribution systems, broadband power-line systems and/or fiber opticnetworks. Additionally, combinations of these devices, systems and/ornetworks may also be used. For example, a combination of twisted-pairand coaxial cable interfaced via a balun connector, or any otherphysical-channel-continuing combination such as an analog fiber tocopper connection with linear optical-to-electrical connection at anOptical Network Unit (ONU) may be used.

The phrases “coupled to,” “coupled with,” connected to,” “connectedwith” and the like are used herein to describe a connection between twoelements and/or components and are intended to mean coupled/connectedeither directly together, or indirectly, for example via one or moreintervening elements or via a wired/wireless connection. References to a“communication system” are intended, where applicable, to includereference to any other type of data transmission system.

FIG. 2A illustrates an alternative exemplary architecture 200 in whichembodiments may operate. FIG. 2A depicts an apparatus 170 which iscommunicably interfaced to a first end of a Digital Subscriber Line (DSLline) 250, for example, through an interface 226 of the apparatus 170.Apparatus 170 includes several components which are interconnectedthrough a data bus 225.

In accordance with one embodiment, apparatus 170 includes: an impulsenoise detector 205 to detect impulse noise 221 affecting communicationson the DSL line 250; a classifier 210 to classify the detected impulsenoise 221 into one of a plurality of impulse noise classes 222; aselection engine 215 to select a noise mitigation strategy 223 fromamong a plurality of noise mitigation strategies 223 based on theimpulse noise class 222 of the detected impulse noise 221; an impulsenoise mitigator 220 to apply the selected noise mitigation strategy 223to generate a corrected signal; a validator 230 to validate applicationof the noise mitigation strategy 223 based on the corrected signal 224;and a multiplexor (MUX) 235 to release the corrected signal 224 onto theDSL line 250 when the validator 230 positively validates application ofthe noise mitigation strategy 223.

Canceling non-stationary noises requires the cancellation of noise thatcomes and goes in contrast to noise which is exhibited as persistent,constant, and predictable interference (e.g., stationary). Interferencenoise associated with AM radio and crosstalk are therefore notconsidered impulse noise as they do not exhibit non-stationarycharacteristics, given that each is relatively constant. In accordancewith one embodiment, detecting impulse noise 221 includes detecting animpulse noise 221 which is characterized as one of: (a) a narrowbandnon-stationary noise causing interference on a narrow range of spectrum;or (b) a broadband non-stationary noise causing interference across abroad range of spectrum. For example, noise associated with HAM radio(also known as amateur radio) is narrowband because it occupies arelatively small range of wireless spectrum and is non-stationarybecause the noise corresponds to intermittent communications over radioequipment by HAM radio operators. Various types of impulse noise willgenerally require or benefit from specialized impulse noise mitigationtechniques.

Impulse noise may further be characterized as non-stationary noise of avery short duration (e.g., typically milliseconds in duration but can beseconds in duration as with, for example impulse noise associated withHAM radio). For example short duration may be one that is less induration than the ADSL signaling superframe of the physical layer.

In one embodiment, detecting impulse noise 221 includes detecting theimpulse noise in real-time. In contrast to long-term interferencemitigation strategies for predictable and consistent stationary noiseaffecting the DSL line 250, impulse noise must be detected and actedupon quickly if the mitigation attempt is to have a benefit to theactive DSL communications on the DSL line 250. Because the impulse noise221 event is of such a short duration, waiting any significant period oftime allows the impulse noise event to negatively affect the DSL line250 without the opportunity to immediately mitigate the event. Thus,real-time mitigation strategies are optimal. This is in contrastsolutions which address persistent, predictable, and stationary typenoises (e.g., not “impulse” type noises) by introducing, for example,interleaving and other related mitigating strategies. Even forstationary noises (persistent, predictable), “real-time” noisecancellation may be implemented. However, because such noises arestationary, it is not necessary to “control” the noise canceller in realtime. On the other hand, for non-stationary noises, because the impulsenoises come and go and because the types of impulse changes from time totime, it becomes necessary “control” the noise cancellation in realtime. Control of noise canceling strategies for persistent noises may beimplemented by adapting filters. For impulse noises, a much tighter andmore responsive control is necessary since the cancellation strategieschange abruptly. Thus, in accordance with one embodiment, the impulsenoise mitigator 220 applies or implements a short-term impulse noisemitigation strategy 223 responsive to detecting the impulse noise inreal-time.

In one embodiment the apparatus 170 further communicates instructions toterminate a long-term noise mitigation strategy affecting operationalparameters of the DSL line. For example, the apparatus 170 maycommunicate such instructions internally via the data bus 225 or maycommunicate such instructions to another entity via interface 226. Inaccordance with one embodiment, a short-term impulse noise mitigationstrategy includes a defined duration to remain in effect. Thus, ashort-term impulse noise mitigation strategy will self terminate orcease to have any affect after its defined duration. In such anembodiment, a long-term noise mitigation strategy remains in effectuntil terminated. Thus, a long-term noise mitigation strategy isimplemented for an indefinite period and does not have a definedduration to remain in effect. In accordance with one embodiment, theapparatus 170 may additionally communicate instructions to implement along-term noise mitigation strategy affecting operational parameters ofthe DSL line 250.

In one embodiment, the long-term strategy noise mitigation involves useof an interleaver. With impulse noise mitigation strategies, it may beadvantageous to turn off the interleaver improve the latency of thecommunications on the DSL line 250. In addition to instituting ashort-term mitigating strategy for the detected impulse noise 221 event,long term strategies and solutions may be communicated to highercommunication protocols. Such higher protocols may then observe thecommunicated long term strategy and issue instructions responsively, yetwill not themselves seek to institute changes for canceling the impulsenoise 221 event which is to be mitigated through the short-term impulsenoise mitigation strategy selected and applied. Long term strategies mayinvolve gathering statistics over time regarding the operation of theDSL line and issuing changed code parameters based on the gatheredstatistics.

In one embodiment, communicating the instructions to implement along-term noise mitigation strategy includes sending instructions toalter Error-Correcting Code (ECC) parameters based on detecting theimpulse noise 221 affecting the DSL line 250. For example, althoughlong-term strategy changes to ECC parameters do not address thereal-time detection and mitigation of an impulse noise 221 event, theECC strategy may nevertheless be improved based on impulse noiseobservations.

FIG. 2B illustrates an alternative exemplary architecture 201 inaccordance with which embodiments may operate. In particular, a firstDSL line 250A and a second DSL line 250B are expressly shown, upon whichDSL signals 299 are carried by the first DSL line 250A and impulse noiseis carried (e.g., detected) via the second DSL line 250B. Additionalsuch lines could further be utilized. According to one embodiment, thefirst DSL line 250A is an active DSL line carrying DSL signals and thesecond DSL line is an inactive DSL line upon which no DSL signals arepresent, with the exception of those associated with interference fromneighboring DSL lines, for example, through crosstalk, etc. In oneembodiment, either or both lines may be twisted pair telephone lines,for example, having two wires each.

According to a specific embodiment, methods and techniques as describedherein are performed by an apparatus for removing interference noisefrom signals on the DSL line 250A, in which the apparatus includes(e.g., shown at FIG. 2B as an “impulse noise mitigator 220), and furtherin which the interference canceller is coupled or communicablyinterfaced with the first DSL line 250A and is further coupled with asecond line, the second DSL line 250B as shown here, in which the secondline (second DSL line 250B) detects the impulse noise 221 affecting thecommunications on the first DSL line 250A. For example, impulse noise221 affecting DSL signals 299 carried by the first DSL line 250A.

According to one embodiment, methods and techniques as described hereinare performed by a modem coupled with the first DSL line 250A. Forexample, the apparatus 170 may be embodied by a modem, such as a CPEmodem. In such an embodiment, the modem is further coupled with a secondDSL line 250B, and the first and second DSL lines 250A-B each areselected from at least one of an active DSL line or an inactive twistedpair telephone line.

FIG. 2C illustrates an alternative exemplary architecture 202 inaccordance with which embodiments may operate. Specifically, anapparatus is depicted as a modem 271 in accordance with at least onembodiment. The figure provides a schematic block diagram having therelevant portions of a DSL modem operating with multiple DSL lines/loopscoupled to the modem and implementing one or more methods, systemsand/or other embodiments set forth herein.

In one embodiment, the modem 271 is connected with multiple telephonelines or DSL lines, as shown, for example, in the drop or shared segment260 between pedestal 204 and modem 271. In such a case, one or morewires of the DSL lines connecting the CPE modem 271 to the pedestal 204may be used as an interference collector, for example, the wires may beutilized to receive and impulse noise for detection or other radiofrequency (RF) noise. In the depicted embodiment, modem 271 is connectedto pedestal 204 by a multiple loop segment 206 of segment 260 having, inthis depicted embodiment, 8 wires 281 through 288, which represent the 8wires (281, 282, 283, 284, 285, 286, 287, and 288) of 4 loops (291, 292,293, and 294), resulting in multiple loop segment 206 of shared segment260.

In the example shown, only loop 294 (using wires 287 and 288) is active,with loops 291, 292, and 293 each being inactive. Thus wires 281 through286 are not in use for DSL communication purposes, that is, they are notactive DSL lines and do not carry a DSL signal. Instead, at least one ofthese wires, wire 286, is used as an interference collector for modem271. In this case, wire 286 is practically identical to wires 287 and288 of active loop 294 (for example, being approximately the same lengthand having the same orientation, possibly being the same material/typeof wire, and possibly having the same amount or absence of shielding)given that it is within the same drop or shared segment 260. This meansthat wire 286 will receive practically identical RF and/or otherinterference signals as those received by loop 294. Where more than onesource of RF and/or other interference (for example, crosstalk from oneor more additional DSL lines) is present, additional inactive loops'wires can be connected with interface 226 and used similarly, ifdesired.

The interference data collected by via interference collector wire 286and the incoming data from the active DSL loop 294 is converted fromanalog to digital form by ADC converters 242 which is communicablyinterfaced to interface 226. The interference noise data is filtered byfilter 241, which bases its conditioning of the interference noise onthe output of subtractor 240. The received data from loop 294 can bedelayed by delay element 243. The conditioned data from loop 294 andinterference collector wire 286 is then input to subtractor 240 so thatthe interference noise can be removed and the remaining user data passedon to the remaining modem components, modules and/or processing 298. TheADCs 242, filter 241 subtractor 240 depicted represent exemplarycircuitry of an impulse noise mitigator 220 in accordance with oneembodiment.

In certain embodiments, additional interference collector wires can bebrought into service using other wires from inactive loops of themultiple loop segment 206. For example, as shown by the dashedconnections 254, wires 283, 284, and 285 can similarly be employed asneeded. ADC(s) 242 may then be more than just a single converter and mayinstead be any suitable conversion circuitry, as will be appreciated bythose skilled in the art. Similarly, in such a case, filter 241 may beadaptive filtering circuitry, as will be appreciated by those skilled inthe art. Finally, multiple wires in the multiple loop segment 206 can beused to remove interference. Such wires may be referred to as “channels”or “reference channels” or “reference signals,” in accordance with themethods and techniques described herein, such as the reference orprimary signals 502A and 502B set forth at FIG. 5 and the primary signal610A and reference signals 610B-610C as set forth at FIG. 6. Inaccordance with one embodiment, any of the wires associated with active294 or the inactive 291, 292, and 293 loops or lines may be utilized toprovide extra twisted pair telephone lines and/or interference collectorwires for use in canceling interference in more than one telephone lineemployed as an active DSL line, for example, where such other active DSLlines are bonded and vectored.

Where a DSL system has available to it additional loops or lines for useas interference collector wires, the RF or other noise and/orinterference may be canceled in across all the active DSL lines. In theexample depicted here, there are 8 wires in the multiple loop segment206, only two of which are in use, the two used for loop 294. Thus,according to an exemplary embodiment, the other 6 wires may be used asfollows: Interference collector wire 286 for collecting RF interferencedata, and wires 281-285 (all associated with inactive lines) are thenused for collecting interference data for the 5 most significantcrosstalkers affecting active loop 294. That is, in a system having Ntelephone loops or lines available, where one of the telephone loops isthe active DSL line, one or more wires in the remaining N−1 loops may beutilized as the interference collector wire or interference collectionmeans to collect interference data. Because there are 2 wires in eachloop, there are 2(N−1) wires available for collecting interference dataaffecting the signals received by modem 271 using the active DSL line.Any suitable interference canceling means can be used in connection withthe interference collector wire(s), including more than one type ofinterference canceling structure where more than one type ofinterference noise is being removed and/or canceled. Each wire can beused to remove a single source of interference noise or impulse noise(for example, AM radio interference, a household appliance near thesegment 260, crosstalk, etc.). Each wire's corresponding interferencedata can be converted to digital form and be filtered appropriately.

FIG. 3 illustrates an alternative exemplary architecture 300 inaccordance with which embodiments may operate. FIG. 3 depicts anembodiment of the impulse noise detector 205 from FIG. 2A in furtherdetail. The output of the impulse noise detector 205 is the start andending of a detected impulse noise.

In one embodiment, the impulse noise detector 205 is communicablyinterfaced with a plurality of receivers 311B and 311C, each of theplurality of receivers 311B-C being communicatively interfaced with adistinct one of a corresponding number of reference channels 312B and312C. As shown, impulse noise detector 205 may further include areceiver 311A to receive primary signal 312A.

In one embodiment, detecting impulse noise includes detecting theimpulse noise using one or more reference channels 312B and 312C. Inaccordance with one embodiment, the one or more reference channels 312Band 312C are selected from among one or more of: (a) a common modechannel on the DSL line 250 communicating via differential modecommunication, in which X1 represents the differential modecommunication; (b) a common mode channel on a twisted pair telephoneline co-located with the DSL line 250 which is not used for DSLcommunications and represented by X2; (c) a differential of the twocommon mode channels X1 and X2; (d) a common mode of the two common modechannels X1 and X2; (e) a differential mode channel on a twisted pairtelephone line co-located with the DSL line 250 which is not used forDSL communications; (f) a reference signal sourced from an antenna; and(g) a reference signal sourced from one or more power lines.

Reference channels and reference signals 312B and 312C may be taken fromany or all of the above sources and are relevant to impulse noisedetection as each is capable to pick up relevant noise signatures. As aresult of having multiple reference signals 312B and 312C, the impulsenoise detector 205 will have improved impulse noise detectioncapabilities. The DSL line 250 itself is contaminated with the DSLcommunication signal at high power, and thus, detection of impulse noise221 events using only the primary signal 312A may be more difficult.However, detection capabilities which leverage multiple referencechannels or reference signals 312B and 312C in addition to the primarysignal 312A on the DSL line 250 can apply different weights to thedifferent reference signals 312B and 312C and combine them to improvedetection and identification of an impulse noise event.

Thus, in accordance with one embodiment, detecting impulse noise 221includes multi-channel impulse noise detection based on multiplereference channels or multiple reference signals 312B and 312C. Furtherdepicted are single channel analysis blocks 313A, 313B, and 313C foreach of the respective primary signal 312A and reference signals 312Band 312C. Each single channel analysis block 313A-C may further indicatea start and end time of a detected impulse noise 221 event. Detectionresult block 314 then applies the analysis output based on the providedanalysis of the single channel analysis blocks 313A-C.

FIG. 4 illustrates an alternative exemplary architecture 400 inaccordance with which embodiments may operate. FIG. 4 depicts additionaldetail of a single channel analysis block, such as the single channelanalysis blocks 313A-C depicted at FIG. 3.

As shown, various functional blocks enable the generation and output ofstatistics 446 for the reference signal or primary signal analyzed. Forinstance, in one embodiment, processing within the single channelanalysis 401 block includes stationary noise suppression 405, powerestimation 410, average 415, threshold detection 420, start detection425, gradient filter 430, peak detector 435, and end detection 440.Impulse statistics collection 445 then generates and outputs statistics446 including, for example, energy, duration, correlation, and so forth.

FIG. 5 illustrates an alternative exemplary architecture 500 inaccordance with which embodiments may operate. FIG. 5 depicts howmultiple classifiers 210 may operate in concert to provide informationto a selection engine 215 which then renders a decision as to whichamong a plurality of impulse noise mitigation strategies 528 isselected.

In accordance with one embodiment, classifiers 501A and 501B areutilized, in which each of the classifiers 501A and 501B includes adelay 510 block and canceller (e.g., a filter) 1 515A through cancellerN 515B capable to evaluate reference signals or primary signals 502A and502B as input.

The noise mitigation strategy database 525 stores a plurality of impulsenoise mitigation strategies and also provides classifier configurations526 to each of the classifiers 501A-B. Selection engine 520 renders adecision as to which of a plurality of noise mitigation strategies tochoose based on input from the classifiers 501A and 501B and basedfurther on cancellation configuration 527 from the noise mitigationstrategy database 525. In another embodiment, rather than utilizingcancellation configuration 527, selection engine 520 may utilize a noisedatabase (e.g., 705A-C as set forth at FIG. 7) which containsinformation on noise statistics including previous cancellation results.For instance, one example may be the use of periodicity informationavailable from the database to predict when the next impulse will hitand then implement preemptive cancellation.

The selection engine 520 then outputs the selected noise mitigationstrategy 528. In accordance with one embodiment, the apparatus 170retrieves the plurality of noise mitigation strategies from the noisemitigation strategy database 525 operating as a remote database.

Classification may be based upon cancellation, however, other featuresor techniques may be utilized such as covariance. For example, usingcancellation, noise may be canceled in one of the reference signals502A-B using noise taken from another reference signal 502A-B.Cancellation may also be implemented using a predictive configuration.With predictive configuration, the signal in 502A and 502B areidentical. Therefore, the canceller filter (515A-515B) become a linearprediction filter. Unlike other configurations, this predictiveconfiguration can test only the autocorrelation of the impulse noise ina particular channel.

In one embodiment, a classification filter is applied one of the signals(either a primary signal or a reference signal) and then the filteredoutput is subtracted from another signal (either a primary signal or areference signal). Based on the subtraction, an energy reduction iscalculated to determine effectiveness or to grade and rank the relativeeffectiveness where multiple filters and reference channels areutilized.

In another embodiment, each of a plurality of classification filtersrepresents an impulse class. However, in some embodiments there may bemore than one classification filter per impulse class. For example, oneclassification filter may be used to test-cancel the impulse in commonmode by using differential mode such that that input to theclassification filter is differential mode and the output is applied tocommon mode. Another classification filter may then be used totest-cancel the impulse in powerline by using common mode. Thetest-cancellation results may then be merged, and then classification ofthe impulse noise event will based on the merged result.

The classifiers 501A-B may apply different solutions, such as multipleshort classification filters associated with different availableclasses, thus producing a variety of results which may later be subjectto validation, grading, and ranking. For example, different solutionsmay be applied to the available reference channels and then the resultsmay be checked to determine whether or not a particular classificationfilter is successful and additionally be graded and ranked so as todetermine which of multiple successful classification filters worksbest. Multiplexer 235 may then be controlled to select the best output.

One means for determining success is to measure the energy output of anoutput signal. For example, if the energy output of the output signal isless than a corresponding input, then cancellation may have providedsome beneficial cancellation on the applicable reference line whichcould also benefit the primary signal communications on the DSL line.Although the DSL communication channel of the DSL line may itself beevaluated, it is often beneficial to use at least one or more referencechannels to perform the classification operation as the referencechannels will not be saturated with high energy DSL signals carryingpayload data.

Evaluation of the active DSL line is nevertheless feasible, for example,by evaluating a common mode of the DSL line given that the DSL linecommunicates via differential mode. Thus, where as the DSL communicationchannel may exhibit a high level of total energy, the common mode on thesame physical DSL line may exhibit a significantly lower level of totalenergy, and is therefore a feasible source detecting and classifyingimpulse noise.

In one embodiment, one of classifiers 501A-B determines that acold-start condition exists and the selection engine 520 responsivelyidentifies a cold-start default class specifying a default filtercalculation as the noise mitigation strategy to apply a default filtercalculation.

Upon identification of a cold-start condition, noise mitigation strategymay not be available, and thus, the original signal may simply beallowed to pass through or be selected at the MUX, despite the existenceof the impulse noise event on the DSL communication signal. Statisticsassociated with the unknown type of impulse noise event may be gatheredand the actual waveform itself may be captured, and then such data isprovided to an entity with more resources to work on the problem andupdate the noise mitigation strategies appropriately. For example, suchinformation may be communicated to a remote server which provides such aservice or collected and stored locally by a signal conditional devicewhich implements such a function. Although the immediately encounteredimpulse noise is not mitigated, over time the collection of such datawill nevertheless improve service overall.

Because more than one reference signal may be utilized at the same time,more than one cancellation filter may also be actively used, thusestablishing a multi-reference structure in the hardware.

Thus, in accordance with one embodiment, classifying the detectedimpulse noise includes: (a) applying distinct classification filters toone of a plurality of reference channels, in which each of the distinctclassification filters correspond to a different class; (b) gradingeffectiveness (e.g., via a validator) of each of the distinctclassification filters based on a decrease of energy output from each ofthe plurality of reference channels; and (c) ranking the distinctclassification filters based on the grading to establish aclassification for the detected impulse noise.

FIG. 6 illustrates an alternative exemplary architecture 600 inaccordance with which embodiments may operate. FIG. 6 depicts howpre-processing may be applied to an incoming primary signal andreference signals. Here an apparatus 170 is depicted as having multiplepre-processors 605A, 605B, and 605C, to apply pre-processing to primarysignal 610A and reference signals 610B and 610C.

The multiple pre-processors 605A-C provide pre-processed variants of theprimary and reference signals 610A-C to other functional blocks as shownwithin the depicted embodiment of apparatus 170, including impulse noisedetector 205, noise characteristics 620, noise classification 625, andimpulse noise mitigator 220. Noise classification 625 provides aclassification 626 of the impulse noise 221 to the impulse noisemitigator 220 which performs cancellation utilizing the plurality ofnoise mitigation strategies 223 as described previously. Validator 230and MUX 235 are additionally shown. Validator 230 controls the MUX 235such that when validator 230 positively validates the impulsecancellation, the MUX 235 output will be the output of impulse noisemitigator 220. Otherwise, where validator 230 does not positivelyvalidate the impulse cancellation, then validator 230 will cause MUX 235to output primary signal 605A.

In accordance with one embodiment, a pre-processor 605A-C of theapparatus pre-processes a signal 610A-C before the impulse noisedetector 205 evaluates the DSL line 250 to detect the impulse noise 221.In such an embodiment, pre-processing is based on prior knowledge of anoperational environment associated with the DSL line 250 when theoperational environment is free of impulse noises. Pre-processing mayprovide narrowband noise cancellation of stationary noise prior toapplication of the selected noise mitigation strategy 223.

Pre-processing based on the environment may include information such aswhich AM signals affect DSL communications for the DSL line 250.Pre-processing removes the stationary and persistent noise componentbefore processing is directed toward cancellation of the impulse noise221 coefficient. For example, pre-processing may be appropriate forpersistent AM signals which are stationary signals rather than impulsetype non-stationary signals because the AM signal waveforms areidentifiable and may therefore be subtracted out.

In one embodiment, the pre-processing is only applied to a re-generatedoutput signal which is limited to looking for only sinusoid signals.

Filters can be selected which make it easier to detect the impulse noise221 events. However, applying filtering to the primary signal 610A onthe DSL line 250 may cause problems where it becomes necessary to undothe filtering to keep the DSL signal integrity. Thus, an original ornon-filtered signal or copy of the primary signal 610A may bemaintained. Alternatively, the change in spectrum induced from filteringmay be whitened to reverse the filtering effects. In one embodiment,both narrowband noise cancellation and filtering are applied before theimpulse noise detector 205 evaluates for an impulse noise 221 event butonly a narrowband noise cancellation is applied to a signal prior to theimpulse noise mitigator 220 which applies the selected noise mitigationstrategy.

Thus, in accordance with one embodiment, the classifier classifies thedetected impulses based on pre-processed signals. In another embodiment,the classifier includes, or is interfaced with, a plurality of receiverscommunicatively interfaced to a corresponding number of referencechannels.

Additionally depicted is the powerline timing 640 block. ConventionalDSL components avoid additional receivers, such as receivers on thecommon mode, because the additional circuitry is more costly toimplement. However, efforts to mitigate impulse noise events may beaided by the receipt and evaluation of reference signals 610B-C fromsources that are distinct from the DSL communication signal (primarysignal 610A) which is saturated with payload information transmitted athigh powers. Therefore, alternate sources (reference signals 610B-C) canprove beneficial despite the issue of additional cost and complexity.

Such alternative sources may include, for example, a common mode signalon the same DSL line or differential and common mode signals fromdifferent lines including a telephone line which is not used for DSLcommunication, as well as power lines, antennas, etc. An apparatusconducting impulse noise mitigation can therefore be communicativelyinterfaced to such reference channel sources so as to receive andevaluate them as part of the impulse noise detection and mitigationoperations. In another embodiment, a powerline signal near the DSL line250 may be used to provide information about the impulse noises, such asignal may be provided by powerline timing block 640. Especially whenthere is powerline based LAN (Local Area Network), the powerline LAN maycreate impulsive noises to DSL line 250. Using a powerline signal frompowerline timing block 640, the impulsive noises originating from thepowerline LAN and be systematically cancelled. Further still, using thepowerline signal from powerline timing block 640, impulse noises may beclassified based on whether a given impulse noise 221 event isattributable to the powerline LAN or to another source, which thussimplifies the classification and clustering operations. In detectingimpulse noise 221 events, whether attributable to powerlinecommunications or otherwise, information from the powerlinecommunications, such as packet header information, may be captured andused in the impulse noise classification functions.

Further depicted is DSL timing 645 block and synchronization maintainingsignal 650 which is inputted to the MUX 235. Such information may beutilized where an uncorrectable impulse noise event is detected. Theinjected synchronization signal may be a convolution of the estimatedchannel and a so called synchronization symbol (for example, as definedin Section 7.11.3 of the G.992.1 standard), the injection enabling aproperly maintained super-frame synchronization and symbolsynchronization. In accordance with one embodiment, classifying thedetected impulse noise into one of a plurality of impulse noise classesincludes: (a) determining that an un-correctable impulse noise event hasbeen detected; (b) identifying a DSL signal synchronization classspecifying a replacement of the communications on the DSL line with aDSL synchronization signal as the noise mitigation strategy; and (c)replacing the communications on the DSL line with the DSLsynchronization signal for a time duration corresponding to the detectedimpulse noise. For example, the start/end indicators may be used todetermine a duration for which the replacement signal based on the DSLtiming 645 block and synchronization maintaining signal 650 should beused.

Sometimes an impulse noise event is sufficiently severe that without theDSL synchronization maintaining signal 650, the impulse noise 221 eventwill knock a DSL modem offline consequently requiring the DSL modem tore-train. Depending on the particular DSL modem, retraining can takebetween 30 seconds up to several minutes, during which timecommunication of payload data is unavailable. A DSL subscriber orcustomer may therefore observe that Internet access has been lost, whichmay result in customer dissatisfaction and may additionally cause thecustomer to engage technical support leading to increased costs for aDSL operator. Although the DSL modem will eventually return to normalservice on its own through the re-training operation, such eventsundermine a customer's perception of the quality of service provided bythe DSL operator. When an impulse noise event is sufficiently severe toknock a DSL modem offline, it may also be of such severity that itcannot be adequately corrected, especially where it is of an unknowntype lacking a good classification match. Thus, one noise mitigationstrategy for such an impulse noise event is to drop the DSLcommunication signal carrying the impulse such that it cannot reach theDSL modem. However, terminating all communications may also trigger are-training event due to a total loss of synchronization information.Therefore, the synchronization maintaining signal 650 operates as areplacement signal which is void of payload data but which carriesre-generated or synthesized DSL synchronization data which is thenselected at MUX 235 and transmitted onto the DSL line 250 to keep theDSL modem alive for the duration of the impulse noise which is dropped.The trade-off is therefore accepting a definite loss of payload data inexchange for negating a potential DSL modem retrain event. Higher levelprotocols will then coordinate the retransmission of the missing data.

In accordance with one embodiment, the validator 230 determines that anun-correctable impulse noise event has been detected and the validator230 further identifies a DSL signal synchronization class specifying areplacement of the communications on the DSL line with a DSLsynchronization signal as the noise mitigation strategy. In such anembodiment, the DSL timing 645 module provides the DSL synchronizationsignal as the noise mitigation strategy to the MUX 235 whichresponsively releases the DSL synchronization maintaining signal 650onto the DSL line 250.

In one embodiment, the impulse noise mitigator 220 applies the noisemitigation strategy to the communications on the DSL line 250. In oneembodiment, the noise mitigation strategy is applied to one of aplurality of copies of the communications on the DSL line 250 and theMUX 235 selects and releases an un-modified copy of the communications(e.g., primary signal 610A in an unmodified form) onto the DSL line 250at the MUX when the corrected signal 224 is negatively validated.

Validator 230 may further coordinate grading and ranking operations alsoreferred to as scorecarding. For instance, where multiple cancellationstrategies are attempted by the apparatus 170 or multiple variousfilters are applied to signals accessible to the apparatus 170, each ofthe plurality of noise mitigation strategy results or filter output maybe later evaluated to determine what resulting output should be releasedfrom the MUX 235.

Scorecarding at validator 230 may determine that all noise mitigationstrategies attempted are either not correct or not sufficient. Thus, oneembodiment, applying the noise mitigation strategy to the communicationson the DSL line includes applying the noise mitigation strategy to oneof a plurality of copies of the communications on the DSL line and thenselecting and releasing an un-modified copy (e.g., releasing primarysignal 610A) of the communications on the DSL line at the MUX when thecorrected signal is negatively validated or is graded and ranked lesserthan the un-modified copy of the communications on the DSL line.

In accordance with one embodiment, validator 230 updates a cancellationcoefficient for the corrected signal when validation is successful andupdates the selected noise mitigation strategy with the calculatedcancellation coefficient.

In accordance with one embodiment, the validator 230 determines validityand a grade or rank for an attempted noise mitigation strategy based onat least one of the following criteria: (a) validating a correctedsignal when a decrease of total energy is exhibited; (b) validating thecorrected signal when a decrease of energy in excess of a threshold isexhibited; and (c) validating the corrected signal from among aplurality of corrected signals based on the corrected signal having agreatest energy within a specified frequency band corresponding totransmission of the communications on the DSL line.

The apparatus may be embodied in various forms. For example, apparatus170 may be implemented via one of: (a) a chipset of a Customer PremisesEquipment (CPE) modem communicably interfaced with a first end of theDSL line; (b) a chipset of a signal conditioning device physicallyseparate and distinct from a Customer Premises Equipment (CPE) modem, inwhich the CPE modem is communicably interfaced with the first end of theDSL line and in which the signal conditioning device is communicativelyinterfaced to the CPE modem; (c) a controller card configured within aCustomer Premises Equipment (CPE) modem communicably interfaced with thefirst end of the DSL line; and (d) a controller card configured within asignal conditioning device physically separate and distinct from aCustomer Premises Equipment (CPE) modem in which the CPE modem iscommunicably interfaced with the first end of the DSL line and furtherin which the signal conditioning device is communicatively interfaced tothe CPE modem.

In another embodiment, detecting the impulse noise includes detectingthe impulse noise at a Customer Premises Equipment (CPE) modemcommunicably interfaced with a first end of the DSL line and selectingthe noise mitigation strategy from among a plurality of noise mitigationstrategies includes receiving the plurality of noise mitigationstrategies from a database at a service provider physically separate anddistinct from the CPE modem. In one embodiment, the service providercomputes the plurality of noise mitigation strategies on behalf of theCPE modem. In one embodiment, the database at the service provider isaccessible based on a paid service subscription. In one embodiment,apparatus 170 is enabled to verify that it is located between a DSLAMand a CPE modem (or the modem circuitry of a CPE modem having theapparatus 170 embodied therein). For example, if the apparatus 170 isnot properly networked it will make a determination of such a faultyinstallation and provide an appropriate indication.

In another embodiment, the method is implemented via a signalconditioning device physically separate and distinct from a CustomerPremises Equipment (CPE) modem, in which the signal conditioning deviceis communicably interfaced with a first end of the DSL line and in whichthe CPE modem is communicatively interfaced to the signal conditioningdevice. In such an embodiment, the signal conditioning deviceiteratively computes and updates the stored noise mitigation strategieswhen excess computational resources are available. Such a signalconditioning device may be co-located at a customer premises with theCPE modem. In one embodiment, such a signal conditioning deviceincludes: (a) a clustering engine to pre-compute the plurality of noisemitigation strategies when excess computational resources are availablewithin the signal conditioning device, (b) store the plurality of noisemitigation strategies within a database of the signal conditioningdevice, (c) provide the plurality of noise mitigation strategies to theselection engine, and (d) enable the signal conditioning device to testfor faulty installation scenarios to ensure proper functionality byutilizing hardware to transmit/receive probing signals and couple themwith the DSL line side and modem side of the signal conditioning device.

In one embodiment, the clustering engine operates physically remote fromthe apparatus and is operated by a third party distinct from asubscriber of the DSL line and distinct from an operator of the DSLline.

FIG. 7 illustrates an alternative exemplary architecture 700 inaccordance with which embodiments may operate. FIG. 7 depicts aclustering engine 701 in further detail. For instance, a noisemitigation strategy may be available for each of the depicted lines.Given N lines, a corresponding N sets of strategies will be availablewhere each of the N sets contains multiple strategies to be used for aparticular one of the N lines.

Depicted within clustering engine 701 are noise databases includingnoise database line 1 705A and noise database line 2 705B through noisedatabase line N 705C, each having noise characteristics 706 (e.g.,duration, energy, time of arrival, etc.) as input and further havingnoise samples and correlation functions 707 as input. Previouscancellation results 708 may also be input into the noise databases705A-C, for example, available from apparatus 170 or from other sources,such as a monitoring entity.

Previously received and stored impulse noise events from the noisedatabases 705A-C are provided to the clustering 725 blocks which clusterthe plurality of impulse noise events into groups resulting in clusters708A, 708B, and 708C, respectively, representative of the impulse noiseevents provided by the noise databases 705A-C. Multiple clusters perline may be utilized. Moreover, clustering may be computed for everyline which results in different clustering strategies for the differentlines. Configuration Wizard (based on clustering results) 730 appliesvarious cancellation strategies against the clusters 708A-C resulting inthe classification and mitigation solutions per cluster (or strategies)709A-C which are then provided to and stored within the noise mitigationstrategy as stored impulse noise mitigation strategies. The intermediateblock 730 allows for only a subset of impulses noises to be used tocompute the actual impulse noise cancellation filter coefficients. Forexample, the impulse noises that re collected during so-called DSL syncsymbol period may be used for computing the cancellation filtercoefficients.

In accordance with one embodiment, the clustering engine 701: (a)receives information about a plurality of observed impulse noise events(multi-channel samples, multi-channel correlation functions and eventcharacteristics) extracted from each of at an apparatus 170; (b)clusters previously observed impulse noise events into groups (e.g.,groups in which group members benefit from sharing the same impulsenoise mitigation solution 708A-C) based at least in part on theinformation extracted from each of the observed impulse noises andreceived by the clustering engine 701; (c) computes a plurality of noisemitigation strategies from the clustered impulse events usinginformation supplied about the these impulse noise events forclassification and mitigation; (d) provides a plurality of impulse noisemitigation strategies as impulse classification strategies to aselection engine 215 of the apparatus 170 for classification, and (e)provides a plurality of impulse noise mitigation strategies as impulsemitigation strategies to cancel impulse contributions on the DSL line250. In accordance with one embodiment, the apparatus 170 includes acontrol interface 775 (such as interface 226 depicted at FIG. 2) tocommunicate characteristics extracted from each of the observed impulsenoises to a clustering engine remote from the apparatus.

The clustering engine and its depicted database may be remote from theapparatus 170. Thus, in one embodiment, the clustering engine providesthe plurality of noise mitigation strategies and classification 776 tothe selection engine of the apparatus by storing the plurality of noisemitigation strategies into a database 525 remote from the apparatus andby sending the plurality of noise mitigation strategies to the controlinterface 775 of the apparatus 170 from the database 525. In analternative embodiment, the clustering engine 701 and the database 525are local to the apparatus 170 or embodied within the apparatus 170.

In one embodiment, the apparatus further includes a collector 780 tocollect new samples 777 of impulse noises. Such samples may be inputinto the noise databases 705A-C. In one embodiment, the controlinterface 775 uploads the new samples 777 of impulse noises to theclustering engine. In one embodiment, the clustering engine 701 updatesthe plurality of noise mitigation strategies and classification 776stored in the database based on the new samples 777 of impulse noisesuploaded to the clustering engine 701.

In one embodiment, the classifier of the apparatus 170 determines thatan unknown type of impulse noise event has been detected and thecollector 780 captures and sends a waveform of the unknown type ofimpulse noise event to the clustering engine via the control interface775.

Because impulse noise samples may be collected and uploaded to theclustering engine, the noise mitigation strategies may be improved andcustomized to a particular operational environment over time, and thus,in accordance with one embodiment, the plurality of noise mitigationstrategies stored within database 525 change over time as do theplurality of noise mitigation strategies held by the selection engine215. Similarly, the plurality of noise mitigation strategies when storedwithin a client device, such as apparatus 170 of FIG. 1, change overtime, whether integrated with a CPE modem, terminal equipment, etc.Furthermore, noise mitigation strategies may be improved in real-timeper impulse occurrence by iterative methods. These range from improvingall of the noise mitigation strategies by iterations and then selectingthe best, or selecting the best strategy and performing iterations onone strategy only. The ability to perform iteration based improvementsis dictated by the constraints of the platform and how to performiterations depends on how close the strategy results are relative toeach other. In accordance with one embodiment, the iteration engine 799implements iterative techniques on behalf of a clustering engine toperform iterative improvement over time to the noise mitigationstrategies.

Because impulse noise samples may be collected and uploaded to theclustering engine, the noise mitigation strategies may be improved andcustomized to a particular operational environment over time, and thus,in accordance with one embodiment, the plurality of noise mitigationstrategies stored within database 525 change over time as do theplurality of noise mitigation strategies held by the selection engine215.

Clustering involves the grouping of many impulse noise events in whichthe greater the population the better a strategy may be derived, butadditionally, the greater the population the more complex the problem ofclustering becomes. For example, given thousands of observed impulsenoise events, conventional techniques would require the calculation anddetermination of a corresponding number distinct cancellation schemesresulting in thousands of distinct cancellation schemes and an immensecomputational burden. However, it is not computationally feasible tocalculate such noise mitigation strategies in real-time. Therefore,means are provided to extract characteristics from each of the exemplarythousands of impulse noise events (e.g., via collected samples andcharacteristics 777 as previously observed and collected over time byapparatus 170) and to then group them into clusters 708A-C representingclusters of impulses. Each cluster then has a corresponding strategy forcancellation for the given class or group of clustered impulse noises.In some embodiments, the clusters may be pre-computed for the group ofclustered impulse noises, however, this is not necessarily required

For example, multiple power line events may be observed as impulse noiseevents at, for example, 60 hertz, but such events may not necessarily berelated or be appropriate for a common impulse noise mitigationstrategy. Moreover, each of the available reference channels or sourcesof reference signals may exhibit different characteristics, even for acommon impulse noise event. Thus, clustering allows for aninitialization process by which samples may be collected, grouped, andmitigation strategies can be computed or pre-computed as needed.Subsequent samples collected over time may then be utilized to updateand improve the initially derived mitigation strategies. Powerlinetiming may represent one cluster or multiple clusters. Impulse noiseevents tend to occur at a particular time in the power line signal, suchas at the crest of a 60 hertz signal. Accordingly, periodicity basedstrategies may be employed to detect and correct impulse noises whichoccur at with determinable periodicity. For example, by knowing thetiming of the peaks, the occurrence of impulses may be predicted. Thus,when a vacuum cleaner or a refrigerator's compressor turns on and drawscurrent, repetitive but predictable impulses may occur for 5 or 10minutes, but the timing and characteristics of the respective impulsenoise events can nevertheless be predicted based on the power linecycle, and thus may correspond to an exemplary classification. Otherpower line clusters may be specified to capture different representativecharacteristics of impulse noise events, as may other clusters which areunrelated to powerline type events.

Subsequently, when a new impulse noise is detected during operation ofthe DSL line, rather than attempting to compute a mitigation strategy inreal-time, the detected impulse noise is classified so that it fallsinto one of the available groups, and the corresponding impulse noisemitigation strategy is selected for use in canceling or otherwisehandling the detected impulse noise affecting the DSL line. Clusteringtherefore reduces the computational burden on the apparatus 170 suchthat it is feasible to perform real-time detection and impulse noisemitigation on an actively operating DSL line. Elastic clusters may beimplemented such that it is possible to efficiently split clusters,merge clusters depending on resources available and performance needs.

Thus, in accordance with one embodiment, computing the plurality ofnoise mitigation strategies includes: (a) computing multiple noisemitigation strategies for each of the groups of previously observedimpulse noises and based further on performance of previously attemptedmitigation attempts; (b) comparing each of the multiple noise mitigationstrategies for each of the groups; and (c) assigning one of the multiplenoise mitigation strategies for each of the groups as the noisemitigation strategy for the respective group.

FIGS. 8 and 9 are flow diagrams 800 and 900 respectively, illustratingmethods for impulse noise detection and mitigation in accordance withdescribed embodiments. Methods 800 and/or 900 may be performed byprocessing logic that may include hardware (e.g., circuitry, dedicatedlogic, programmable logic, microcode, etc.), software (e.g.,instructions run on a processing device to perform various operationssuch as interfacing, collecting, generating, receiving, monitoring,diagnosing, analyzing, classifying, validating, or some combinationthereof). In one embodiment, methods 800 and 900 are performed orcoordinated via an apparatus such as that depicted at element 170 ofFIG. 1 and described throughout. In another embodiment, the methodoperations are performed or coordinated by an entity separate fromapparatus, such as a clustering engine 701. Some of the blocks and/oroperations listed below are optional in accordance with certainembodiments. The numbering of the blocks presented is for the sake ofclarity and is not intended to prescribe an order of operations in whichthe various blocks must occur. Additionally, operations from the variousflows 800 and 900 may be utilized in a variety of combinations,including in combination with each other.

Method 800 begins with processing logic for detecting impulse noise atblock 802.

At block 804, processing logic classifies the detected impulse noiseinto one of a plurality of impulse noise classes affectingcommunications on a DSL line.

At block 806, processing logic selects a noise mitigation strategy fromamong a plurality of noise mitigation strategies.

At block 808, processing logic applies the selected noise mitigationstrategy.

At block 810, processing logic validates application of the noisemitigation strategy.

In accordance with one embodiment, there is a non-transitory computerreadable storage medium having instructions stored thereon that, whenexecuted by a processor of an apparatus, the instructions cause theapparatus to perform operations comprising: detecting impulse noiseaffecting communications on a Digital Subscriber Line (DSL line);classifying the detected impulse noise into one of a plurality ofimpulse noise classes; selecting a noise mitigation strategy from amonga plurality of noise mitigation strategies; applying the selected noisemitigation strategy; and validating application of the noise mitigationstrategy.

Method 900 begins with processing logic for receiving data describing aplurality of impulse noises observed by one or more remote apparatusesas set forth at block 950.

At block 952, processing logic clusters the plurality of impulse noisesinto groups.

At block 954, processing logic computes a plurality of noise mitigationstrategies from the groups of the observed impulse noises.

At block 956, processing logic provides the plurality of noisemitigation strategies to each of the one or more remote apparatuses tomitigate future impulse noises observed by the one or more remoteapparatuses

In accordance with one embodiment, there is a non-transitory computerreadable storage medium having instructions stored thereon that, whenexecuted by a processor of an apparatus, the instructions cause theapparatus to perform operations comprising: receiving data describing aplurality of impulse noises observed by one or more remote apparatuses;clustering the plurality of impulse noises into groups; computing aplurality of noise mitigation strategies from the groups of the observedimpulse noises; and providing the plurality of noise mitigationstrategies to each of the one or more remote apparatuses to mitigatefuture impulse noises observed by the one or more remote apparatuses.

FIG. 10 shows a diagrammatic representation of a system 1000 inaccordance with which embodiments may operate, be installed, integrated,or configured.

In one embodiment, system 1000 includes a memory 1095 and a processor orprocessors 1096. For example, memory 1095 may store instructions to beexecuted and processor(s) 1096 may execute such instructions.Processor(s) 1096 may also implement or execute implementing logiccapable to implement the methodologies discussed herein. System 1000includes communication bus(es) 1015 to transfer transactions,instructions, requests, and data within system 1000 among a plurality ofperipheral devices communicably interfaced with one or morecommunication buses 1015. System 1000 further includes managementinterface 1025, for example, to receive requests, return responses, andotherwise interface with network elements located separately from system1000.

In some embodiments, management interface 1025 communicates informationvia an in-band or an out-of-band connection separate from LAN and/or WANbased communications. The “in-band” communications are communicationsthat traverse the same communication means as payload data (e.g.,content) being exchanged between networked devices and the “out-of-band”communications are communications that traverse an isolatedcommunication means, separate from the mechanism for communicating thepayload data. An out-of-band connection may serve as a redundant orbackup interface over which to communicate control data and instructionsbetween the system 1000 other networked devices or between the system1000 and a third party service provider. System 1000 includes LANinterface 1030 and WAN interface 1035 to communicate information via LANand WAN based connections respectively. System 1000 includes clusteringengine 1060 to receive impulse noise samples or characteristics andcluster the impulse noise samples into groups representative of impulsenoises and then compute a plurality of noise mitigation strategies 1050to be stored and then provided to apparatus 1070. Historical informationmay also be stored and analyzed or referenced when conducting long termanalysis and reporting.

Distinct within system 1000 is apparatus 1070 which includes impulsenoise detector 1071, classifier 1072, selection engine 1073, impulsenoise mitigator 1074, validator 1075, and MUX 1076. Apparatus 1070 maybe installed and configured in a compatible system 1000 as is depictedby FIG. 10, or embodied in various forms such as a controller, chip set,CPE modem, signal conditioning device, etc.

While the subject matter disclosed herein has been described by way ofexample and in terms of the specific embodiments, it is to be understoodthat the claimed embodiments are not limited to the explicitlyenumerated embodiments disclosed. To the contrary, the disclosure isintended to cover various modifications and similar arrangements aswould be apparent to those skilled in the art. Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements. It is tobe understood that the above description is intended to be illustrative,and not restrictive. Many other embodiments will be apparent to those ofskill in the art upon reading and understanding the above description.The scope of the disclosed subject matter is therefore to be determinedin reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A method comprising: detecting impulse noise;classifying the detected impulse noise into one of a plurality ofimpulse noise classes affecting communications on a Digital SubscriberLine (DSL line); selecting a noise mitigation strategy from among aplurality of noise mitigation strategies; applying the selected noisemitigation strategy; and validating application of the noise mitigationstrategy.
 2. The method of claim 1, wherein classifying the detectedimpulse noise is based at least in part on a source identificationassociated with the detected impulse noise, wherein the sourceidentification corresponds to a primary channel or one of a plurality ofreference channels.
 3. The method of claim 1, wherein the method isperformed by an apparatus for removing interference noise, wherein theapparatus comprises: an interference canceller coupled with the DSL lineand further coupled with a second line, wherein the second line detectsthe impulse noise.
 4. The method of claim 1: wherein the method isperformed by a modem coupled with the DSL line; wherein the modem isfurther coupled with a second DSL line; and wherein the first and secondDSL lines each comprise at least one of an active DSL line or aninactive twisted pair telephone line.
 5. The method of claim 1, whereindetecting impulse noise comprises an impulse noise characterized as oneof: a narrowband non-stationary noise causing interference on a narrowrange of spectrum; and a broadband non-stationary noise causinginterference across a broad range of spectrum.
 6. The method of claim 1,wherein detecting impulse noise comprises detecting the impulse noise inreal-time.
 7. The method of claim 6, wherein applying the selected noisemitigation strategy comprises at least one of: applying a short-termimpulse noise mitigation strategy responsive to detecting the impulsenoise in real-time, wherein short-term impulse noise mitigation strategyincludes a defined duration to remain in effect; and communicatinginstructions to terminate a long-term noise mitigation strategyaffecting operational parameters of the DSL line; wherein the long-termnoise mitigation strategy remains in effect until terminated.
 8. Themethod of claim 1, further comprising: communicating instructions toimplement a long-term noise mitigation strategy affecting operationalparameters of the DSL line in near real-time.
 9. The method of claim 8,wherein communicating the instructions to implement a long-term noisemitigation strategy comprises sending instructions to alterError-Correcting Code (ECC) parameters based on detecting the impulsenoise in near real-time.
 10. The method of claim 1, wherein detectingimpulse noise comprises detecting the impulse noise using one or morereference channels, wherein the one or more reference channels areselected from among one or more of: a common mode channel on the DSLline communicating via differential mode communication, wherein X1represents the differential mode communication; a common mode channel ona twisted pair telephone line co-located with the DSL line which is notused for DSL communications and represented by X2; a differential of thetwo common mode channels X1 and X2; a common mode of the two common modechannels X1 and X2; a differential mode channel on a twisted pairtelephone line co-located with the DSL line which is not used for DSLcommunications; a reference signal sourced from an antenna; and areference signal sourced from one or more power lines.
 11. The method ofclaim 1, wherein detecting impulse noise comprises multi-channel impulsenoise detection based on multiple reference channels.
 12. The method ofclaim 1, wherein detecting the impulse noise comprises: pre-processing asignal before the signal is evaluated for presence of an impulse noisebased on prior knowledge of an operational environment associated withthe DSL line, wherein the pre-processing provides narrowband noisecancellation of stationary noise prior to applying the selected noisemitigation strategy.
 12. The method of claim 1, wherein detectingimpulse noise comprises: filtering a signal from each of one or morereference channels; detecting the impulse noise using the one or morereference channels by evaluating signals from one or more referencechannels for the impulse noise.
 14. The method of claim 13, where asignal from each of the one or more reference channels is pre-processedbased on prior knowledge of an operational environment associated withthe DSL line when there is no impulse noise, wherein the pre-processingprovides stationary noise prior to applying the selected impulse noisemitigation strategy.
 15. The method of claim 1, wherein classifying thedetected impulse noise into one of a plurality of impulse noise classescomprises a classifier communicatively interfaced to a plurality ofreceivers, each of the receivers communicatively interfaced to acorresponding one of a plurality of reference channels.
 16. The methodof claim 1, wherein the plurality of noise mitigation strategies changeover time via iterative processing.
 17. The method of claim 1, whereinthe method further comprises: clustering previously observed impulsenoises into groups based on characteristics extracted from each of theobserved impulse noises; computing the plurality of noise mitigationstrategies from the groups of the previously observed impulse noises;and providing the plurality of noise mitigation strategies to aselection engine which selects the noise mitigation strategy from amongthe plurality of noise mitigation strategies.
 18. The method of claim17, wherein the method further comprises: collecting new samples ofimpulse noises; and updating the plurality of noise mitigationstrategies based on the new samples of impulse noises.
 19. The method ofclaim 17, wherein computing the plurality of noise mitigation strategiescomprises: computing multiple noise mitigation strategies for each ofthe groups of previously observed impulse noises and based further onperformance of previously attempted mitigation attempts; comparing eachof the multiple noise mitigation strategies for each of the groups; andassigning one of the multiple noise mitigation strategies for each ofthe groups as the noise mitigation strategy for the respective group.20. The method of claim 1, wherein each of the plurality of noisemitigation strategies includes a cancellation filter to be applied tothe communications on the DSL line based on a distinct reference channelcorresponding to each of the plurality of noise mitigation strategies.21. The method of claim 1, wherein classifying the detected impulsenoise comprises: applying distinct classification filters to one of aplurality of reference channels, wherein each of the distinctclassification filters correspond to a different class; gradingeffectiveness of each of the distinct classification filters based on adecrease of energy output from each of the plurality of referencechannels; and ranking the distinct classification filters based on thegrading to establish a classification for the detected impulse noise.22. The method of claim 1, further comprising: retrieving the pluralityof noise mitigation strategies from a remote database.
 23. The method ofclaim 1, wherein applying the selected noise mitigation strategycomprises applying the noise mitigation strategy to the communicationson the DSL line before a multiplexor (MUX) resulting in a correctedsignal.
 24. The method of claim 23, wherein applying the noisemitigation strategy to the communications on the DSL line before the MUXcomprises applying the noise mitigation strategy to one of a pluralityof copies of the communications on the DSL line; and wherein the methodfurther comprises: selecting and releasing an un-modified copy of thecommunications on the DSL line at the MUX when the corrected signal isnegatively validated.
 25. The method of claim 1, further comprising:calculating a cancellation effectiveness measure for the correctedsignal when validation is successful; and updating the selected noisemitigation strategy with the cancellation effectiveness measure.
 26. Themethod of claim 1, wherein classifying the detected impulse noise intoone of a plurality of impulse noise classes comprises: determining thata cold-start condition exists; identifying a cold-start default classspecifying a default filter calculation as the noise mitigationstrategy; and applying the default filter calculation.
 27. The method ofclaim 1, wherein classifying the detected impulse noise into one of aplurality of impulse noise classes comprises: determining that anun-correctable impulse noise event has been detected; identifying a DSLsignal synchronization class specifying a replacement of thecommunications on the DSL line with a DSL synchronization signal as thenoise mitigation strategy; and replacing the communications on the DSLline with the DSL synchronization signal for a time durationcorresponding to the detected impulse noise, wherein payload informationassociated with the communications on the DSL line are lost for the timeduration but synchronization is maintained.
 28. The method of claim 27,further comprising: capturing the un-correctable impulse noise event asa new impulse noise sample; and transmitting new impulse noise sample toan entity which generates the plurality of noise mitigation strategies.29. The method of claim 1, wherein classifying the detected impulsenoise into one of a plurality of impulse noise classes comprises:determining that an unknown type of impulse noise event has beendetected; identifying a DSL signal synchronization class specifying useof the original DSL communication on the DSL line without modificationas the noise mitigation strategy; and communicating the unknown type ofimpulse noise event to an entity which generates the plurality of noisemitigation strategies, wherein the entity is one of a remote entitywhich provides the plurality of noise mitigation strategies or a signalconditioning device which provides the plurality of noise mitigationstrategies.
 30. The method of claim 29, wherein communicating theunknown type of impulse noise event to the entity which generates theplurality of noise mitigation strategies comprises capturing and sendinga wave form of the unknown type of impulse noise event for use inupdating the plurality of noise mitigation strategies.
 31. The method ofclaim 1, wherein validating application of the noise mitigation strategybased on a corrected signal comprises comparing the corrected signalhaving been filtered or subjected to the selected noise mitigationstrategy, or both, with an uncorrected signal.
 32. The method of claim1, wherein the method is implemented via one of: a chipset of a CustomerPremises Equipment (CPE) modem communicably interfaced with a first endof the DSL line; a chipset of a signal conditioning device physicallyseparate and distinct from a Customer Premises Equipment (CPE) modem,wherein the CPE modem is communicably interfaced with the first end ofthe DSL line and wherein the signal conditioning device iscommunicatively interfaced to the CPE modem; a controller cardconfigured within a Customer Premises Equipment (CPE) modem communicablyinterfaced with the first end of the DSL line; and a controller cardconfigured within a signal conditioning device physically separate anddistinct from a Customer Premises Equipment (CPE) modem, wherein the CPEmodem is communicably interfaced with the first end of the DSL line andwherein the signal conditioning device is communicatively interfaced tothe CPE modem.
 33. The method of claim 1, wherein: detecting the impulsenoise comprises detecting the impulse noise at a Customer PremisesEquipment (CPE) modem communicably interfaced with a first end of theDSL line; and wherein selecting a noise mitigation strategy from among aplurality of noise mitigation strategies comprises receiving theplurality of noise mitigation strategies from a database at a serviceprovider physically separate and distinct from the CPE modem.
 34. Themethod of claim 33, wherein the service provider computes the pluralityof noise mitigation strategies on behalf of the CPE modem.
 35. Themethod of claim 33, wherein the database at a service provider isaccessible based on a paid service subscription.
 36. The method of claim1, wherein the method is implemented via a signal conditioning devicephysically separate and distinct from a Customer Premises Equipment(CPE) modem, wherein the signal conditioning device is communicablyinterfaced with a first end of the DSL line and wherein the CPE modem iscommunicatively interfaced to the signal conditioning device; andwherein the signal conditioning device further pre-computes and storesthe plurality of noise mitigation strategies when excess computationalresources are available.
 37. An apparatus comprising: an impulse noisedetector to detect impulse noise; a classifier to classify the detectedimpulse noise into one of a plurality of impulse noise classes affectingcommunications on a Digital Subscriber Line (DSL line); a selectionengine to select a noise mitigation strategy from among a plurality ofnoise mitigation strategies; an impulse noise mitigator to apply theselected noise mitigation strategy; and a validator to validateapplication of the noise mitigation strategy.
 38. The apparatus of claim37, further comprising: a multiplexor (MUX) to release one of aplurality of available signals onto the DSL line as specified by thevalidator.
 39. The apparatus of claim 37, wherein the classifier iscommunicably interfaced with a plurality of receivers, each of theplurality of receivers being communicatively interfaced with a distinctone of a corresponding number of reference channels.
 40. The apparatusof claim 37, further comprising: a control interface to communicatecharacteristics extracted from each of the observed impulse noises to aclustering engine remote from the apparatus.
 41. The apparatus of claim40, wherein the clustering engine is to: receive the characteristicsextracted from each of the observed impulse noises; cluster previouslyobserved impulse noises into groups based at least in part on thecharacteristics extracted from each of the observed impulse noises andreceived by the clustering engine; compute the plurality of noisemitigation strategies from the groups of the previously observed impulsenoises; and provide the plurality of noise mitigation strategies to theselection engine of the apparatus via a control interface.
 42. Theapparatus of claim 41, wherein the clustering engine to provide theplurality of noise mitigation strategies to the selection engine of theapparatus via a control interface comprises the clustering engine to:store the plurality of noise mitigation strategies into a databaseremote from the apparatus; and sending the plurality of noise mitigationstrategies to the control interface of the apparatus from the database.43. The apparatus of claim 40: wherein the apparatus further comprises acollector to collect new samples of impulse noises; wherein the controlinterface of the apparatus is to further upload the new samples ofimpulse noises to the clustering engine; and wherein the clusteringengine is to update the plurality of noise mitigation strategies basedon the new samples of impulse noises uploaded to the clustering engine.44. The apparatus of claim 40: wherein the classifier is to determinethat an unknown type of impulse noise event has been detected; whereinthe classifier is to identify a DSL signal synchronization classspecifying use of the original DSL communication on the DSL line withoutmodification as the noise mitigation strategy; and wherein the collectoris to capture and send a wave form of the unknown type of impulse noiseevent to the clustering engine via the control interface.
 45. Theapparatus of claim 38: wherein the impulse noise mitigator is to applythe noise mitigation strategy to the communications on the DSL linebefore the MUX resulting in a corrected signal; wherein the noisemitigation strategy is applied to one of a plurality of copies of thecommunications on the DSL line; and wherein the MUX is to select andrelease an un-modified copy of the communications on the DSL line at theMUX when the corrected signal is negatively validated.
 46. The apparatusof claim 38: wherein the validator is to determine that anun-correctable impulse noise event has been detected; wherein thevalidator is to identify a DSL signal synchronization class specifying areplacement of the communications on the DSL line with a DSLsynchronization signal as the noise mitigation strategy; and wherein theapparatus further comprises a DSL timing module to provide the DSLsynchronization signal as the noise mitigation strategy to the MUX,wherein the MUX is to responsively release the DSL synchronizationsignal onto the DSL line.
 47. The apparatus of claim 37, wherein theapparatus is embodied within one of: a chipset of a Customer PremisesEquipment (CPE) modem communicably interfaced with a first end of theDSL line; a chipset of a signal conditioning device physically separateand distinct from a Customer Premises Equipment (CPE) modem, wherein thesignal conditioning device is communicably interfaced with the first endof the DSL line and wherein the CPE modem is communicatively interfacedto the signal conditioning device; a controller card configured within aCustomer Premises Equipment (CPE) modem communicably interfaced with thefirst end of the DSL line; and a controller card configured within asignal conditioning device physically separate and distinct from aCustomer Premises Equipment (CPE) modem, wherein the signal conditioningdevice is communicably interfaced with the first end of the DSL line andwherein the CPE modem is communicatively interfaced to the signalconditioning device.
 48. The apparatus of claim 40, wherein theapparatus is embodied within a signal conditioning device physicallyseparate and distinct from a Customer Premises Equipment (CPE) modem,wherein the signal conditioning device is communicably interfaced with afirst end of the DSL line and wherein the CPE modem is communicativelyinterfaced to the signal conditioning device; and wherein the signalconditioning device: (a) includes a clustering engine to pre-compute theplurality of noise mitigation strategies when excess computationalresources are available within the signal conditioning device, (b)stores the plurality of noise mitigation strategies within a database ofthe signal conditioning device, (c) provides the plurality of noisemitigation strategies to the selection engine, and (d) enables thesignal conditioning device to test for faulty installation scenarios toensure proper functionality by utilizing hardware to transmit/receiveprobing signals and couple them with the DSL line side and modem side ofthe signal conditioning device.
 49. The apparatus of claim 37, furthercomprising: a pre-processor to pre-process a signal before the impulsenoise detector evaluates the DSL line to detect the impulse noise;wherein pre-processing is based on prior knowledge of an operationalenvironment associated with the DSL line when there is no impulse noise,wherein the processing provides stationary noise cancellation prior toapplying the selected impulse noise mitigation strategy.
 50. Theapparatus of claim 37, further comprising: a filter to filter noise fromthe signal based on prior knowledge of an operational environmentassociated with the DSL line, wherein the filter is to filter a signalfrom each of one or more reference channels.
 51. A non-transitorycomputer readable storage medium having instructions stored thereonthat, when executed by a processor of an apparatus, the instructionscause the apparatus to perform operations comprising: detecting impulsenoise; classifying the detected impulse noise into one of a plurality ofimpulse noise classes affecting communications on a Digital SubscriberLine (DSL line); selecting a noise mitigation strategy from among aplurality of noise mitigation strategies; applying the selected noisemitigation strategy; and validating application of the noise mitigationstrategy.
 52. A system comprising: an apparatus coupled with a first endof a Digital Subscriber Line (DSL line), the apparatus having therein:an impulse noise detector to detect impulse noise; a classifier toclassify the detected impulse noise into one of a plurality of impulsenoise classes affecting communications on a Digital Subscriber Line (DSLline); a selection engine to select a noise mitigation strategy fromamong a plurality of noise mitigation strategies; an impulse noisemitigator to apply the selected noise mitigation strategy; and avalidator to validate application of the noise mitigation strategy. aclustering engine, wherein the clustering engine is to: receivecharacteristics extracted from each of the observed impulse noises fromthe apparatus, cluster previously observed impulse noises into groupsbased at least in part on the characteristics extracted from each of theobserved impulse noises received by the clustering engine, compute theplurality of noise mitigation strategies from the groups of thepreviously observed impulse noises; and provide the plurality of noisemitigation strategies to the selection engine of the apparatus.
 53. Thesystem of claim 52, further comprising: a database to store theplurality of noise mitigation strategies provided by the clusteringengine.
 54. The system of claim 53: wherein the apparatus comprises oneof a Customer Premises Equipment (CPE) modem connected to the first endof the DSL line or a signal conditioning device connected to the firstend of the DSL line at a Customer Premises location; and wherein theclustering engine operates physically remote from the apparatus by athird party distinct from a subscriber of the DSL line and distinct froman operator of the DSL line.
 55. A method comprising: receiving datadescribing a plurality of impulse noises observed by one or more remoteapparatuses; clustering the plurality of impulse noises into groups;computing a plurality of noise mitigation strategies from the groups ofthe observed impulse noises; and providing the plurality of noisemitigation strategies to each of the one or more remote apparatuses tomitigate future impulse noises observed by the one or more remoteapparatuses.
 56. The method of claim 55, wherein the one or more remoteapparatuses each comprise one of a Customer Premises Equipment (CPE)modem connected to a first end of a Digital Subscriber Line (DSL line)or a signal conditioning device connected to the first end of the DSLline at a Customer Premises location.